Set scrollbar enabled state for overflow:auto.

Set scrollbar enabled state for overflow:auto.

PaintLayerScrollableArea code previously assumed it needed to setEnabled only
on scrollbars for overflow:scroll elements. This was because the only time we
would have a disabled scrollbar was for an overflow:scroll areas without enough
overflow. An overflow:auto area simply wouldn't have created the scrollbar.

This changes for overlay scrollbars because we fade out the scrollbars by
disabling them, causing painting code to avoid painting.

BUG=636392
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4fa58f16e52436c1b547ae6843611ec5cca0f364
Cr-Commit-Position: refs/heads/master@{#433348}

[bokan, 2016-11-17 00:27:15]

Description was changed from

==========
Set scrollbar enabled state for overflow:auto.

PaintLayerScrollableArea code previously assumed it needed to setEnabled only
on scrollbars for overflow:scroll elements. This was because the only time we
would have a disabled scrollbar was for an overflow:scroll areas without enough
overflow. An overflow:auto area simply wouldn't have created the scrollbar.

This changes for overlay scrollbars because we fade out the scrollbars by
disabling them, causing painting code to avoid painting.

BUG=636392
==========

to

==========
Set scrollbar enabled state for overflow:auto.

PaintLayerScrollableArea code previously assumed it needed to setEnabled only
on scrollbars for overflow:scroll elements. This was because the only time we
would have a disabled scrollbar was for an overflow:scroll areas without enough
overflow. An overflow:auto area simply wouldn't have created the scrollbar.

This changes for overlay scrollbars because we fade out the scrollbars by
disabling them, causing painting code to avoid painting.

BUG=636392
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[bokan, 2016-11-17 00:27:44]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-17 00:28:52]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-17 02:44:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 02:44:39]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[bokan, 2016-11-17 13:48:41]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-17 13:48:58]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-17 15:13:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 15:13:36]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[bokan, 2016-11-17 17:01:22]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-17 17:02:07]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[bokan, 2016-11-17 17:04:45]

bokan@chromium.org changed reviewers:
+ skobes@chromium.org

[bokan, 2016-11-17 17:04:46]

Sorry to flood you with scrollbar reviews, feel free to punt to someone else if
you're overloaded :)

https://codereview.chromium.org/2505253002/diff/40001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/paint/invalidation/flexbox/scrollbars-changed-expected.txt
(right):

https://codereview.chromium.org/2505253002/diff/40001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/paint/invalidation/flexbox/scrollbars-changed-expected.txt:61:
"reason": "full"
The extra invalidations come from changing the enabled state on an overflow:auto
scrollbar, which didn't happen before. This shouldn't matter though because if
we've changed the enabled state, the scrollbar is about to be removed which will
cause an invalidation anyway.

[commit-bot: I haz the power, 2016-11-17 20:05:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 20:05:17]

Dry run: This issue passed the CQ dry run.

[skobes, 2016-11-17 21:18:23]

lgtm

https://codereview.chromium.org/2505253002/diff/40001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/paint/invalidation/flexbox/scrollbars-changed-expected.txt
(right):

https://codereview.chromium.org/2505253002/diff/40001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/paint/invalidation/flexbox/scrollbars-changed-expected.txt:61:
"reason": "full"
On 2016/11/17 17:04:45, bokan wrote:
> The extra invalidations come from changing the enabled state on an
overflow:auto
> scrollbar, which didn't happen before. This shouldn't matter though because if
> we've changed the enabled state, the scrollbar is about to be removed which
will
> cause an invalidation anyway.

Acknowledged.

[bokan, 2016-11-17 23:23:02]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-17 23:24:59]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 01:30:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 01:30:19]

Dry run: Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)

[bokan, 2016-11-18 19:11:40]

The CQ bit was checked by bokan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-18 19:12:35]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 23:21:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 23:21:57]

Dry run: Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)

[bokan, 2016-11-18 23:37:13]

The CQ bit was checked by bokan@chromium.org

[bokan, 2016-11-18 23:37:14]

The patchset sent to the CQ was uploaded after l-g-t-m from skobes@chromium.org
Link to the patchset: https://codereview.chromium.org/2505253002/#ps80001
(title: "Rebase")

[commit-bot: I haz the power, 2016-11-18 23:37:56]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-19 00:27:04]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2016-11-19 00:29:52]

Description was changed from

==========
Set scrollbar enabled state for overflow:auto.

PaintLayerScrollableArea code previously assumed it needed to setEnabled only
on scrollbars for overflow:scroll elements. This was because the only time we
would have a disabled scrollbar was for an overflow:scroll areas without enough
overflow. An overflow:auto area simply wouldn't have created the scrollbar.

This changes for overlay scrollbars because we fade out the scrollbars by
disabling them, causing painting code to avoid painting.

BUG=636392
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Set scrollbar enabled state for overflow:auto.

PaintLayerScrollableArea code previously assumed it needed to setEnabled only
on scrollbars for overflow:scroll elements. This was because the only time we
would have a disabled scrollbar was for an overflow:scroll areas without enough
overflow. An overflow:auto area simply wouldn't have created the scrollbar.

This changes for overlay scrollbars because we fade out the scrollbars by
disabling them, causing painting code to avoid painting.

BUG=636392
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/4fa58f16e52436c1b547ae6843611ec5cca0f364
Cr-Commit-Position: refs/heads/master@{#433348}
==========

[commit-bot: I haz the power, 2016-11-19 00:29:53]

Patchset 5 (id:??) landed as
https://crrev.com/4fa58f16e52436c1b547ae6843611ec5cca0f364
Cr-Commit-Position: refs/heads/master@{#433348}